1. Field of the Invention
The present invention relates to electrohydrodynamic (EHD) generators, and more particularly to a multistage EHD generator having parallel outputs.
2. Background of the Invention
An EHD generator has an injector which injects unipolar particles or droplets into a fluid flow. These particles or droplets are ionized by a suitable charging mechanism such as corona discharge, as described in U.S. Pat. No. 3,777,564 issued Dec. 11, 1973 to Oscar Biblarz, entitled "Electrogasdynamic Spectral Anemometer", or ultra-violet (UV) radiation. The fluid flow carrying these charged particles passes through a channel and a collector neutralizes the charge, producing an electric current. The amount of power produced by a simple EHD generator is on the order of 50 watts. This is too small for practical power applications, therefore, various staging techniques have been used to increase the usable power output. One technique has been to use a single injector for a plurality of simple EHD generators in parallel. Another technique has been to use multiple EHD generators connected in series with a separate injector and particle collector for each stage. The disadvantage of the first technique is the low pressure drop across the working fluid. The disadvantage of the second technique is the requirement for multiple particle injectors and collectors.